From patchwork Wed Feb 12 22:30:12 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anchal Agarwal X-Patchwork-Id: 11379251 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0452D921 for ; Wed, 12 Feb 2020 22:31:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CA71B222C2 for ; Wed, 12 Feb 2020 22:31:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="K4QvLvuk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727692AbgBLWbA (ORCPT ); Wed, 12 Feb 2020 17:31:00 -0500 Received: from smtp-fw-2101.amazon.com ([72.21.196.25]:20640 "EHLO smtp-fw-2101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727564AbgBLWbA (ORCPT ); Wed, 12 Feb 2020 17:31:00 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1581546660; x=1613082660; h=date:from:to:subject:message-id:mime-version; bh=lXUfPVCqOw43hJmA37ZNPhgrTtTkVXf8HnLPkdJWiEM=; b=K4QvLvukE4XCZsxDVAajjZadK8oOy2xv3blqAcJviLA1FxH1Vm355R/g Z817rZCdaLXhJfHsf39UC7aQdabgYgVESj0FCHRs28l+uhS428q6NPOiJ QhtL1gyLoi3oEPC3NTGeROCeblX6w2h+RDhlldzVaEwaqAQO6MudT2JJc g=; IronPort-SDR: wj0rP/4g7pIfoN8xmEr/giPmQ1SZih6GVao218XZ5Ck786gidFMD9z9Ffv8EwCVBjqDYTkm3/m i77D21jlZtKg== X-IronPort-AV: E=Sophos;i="5.70,434,1574121600"; d="scan'208";a="16932720" Received: from iad12-co-svc-p1-lb1-vlan2.amazon.com (HELO email-inbound-relay-2b-81e76b79.us-west-2.amazon.com) ([10.43.8.2]) by smtp-border-fw-out-2101.iad2.amazon.com with ESMTP; 12 Feb 2020 22:30:45 +0000 Received: from EX13MTAUWC001.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan3.pdx.amazon.com [10.170.41.166]) by email-inbound-relay-2b-81e76b79.us-west-2.amazon.com (Postfix) with ESMTPS id 5CFCAA2483; Wed, 12 Feb 2020 22:30:43 +0000 (UTC) Received: from EX13D05UWC004.ant.amazon.com (10.43.162.223) by EX13MTAUWC001.ant.amazon.com (10.43.162.135) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:30:13 +0000 Received: from EX13MTAUWC001.ant.amazon.com (10.43.162.135) by EX13D05UWC004.ant.amazon.com (10.43.162.223) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:30:12 +0000 Received: from dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (172.22.96.68) by mail-relay.amazon.com (10.43.162.232) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Wed, 12 Feb 2020 22:30:12 +0000 Received: by dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (Postfix, from userid 4335130) id C890D400D1; Wed, 12 Feb 2020 22:30:12 +0000 (UTC) Date: Wed, 12 Feb 2020 22:30:12 +0000 From: Anchal Agarwal To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [RFC PATCH v3 01/12] xen/manage: keep track of the on-going suspend mode Message-ID: <20200212223012.GA3445@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Munehisa Kamata Guest hibernation is different from xen suspend/resume/live migration. Xen save/restore does not use pm_ops as is needed by guest hibernation. Hibernation in guest follows ACPI path and is guest inititated , the hibernation image is saved within guest as compared to later modes which are xen toolstack assisted and image creation/storage is in control of hypervisor/host machine. To differentiate between Xen suspend and PM hibernation, keep track of the on-going suspend mode by mainly using a new PM notifier. Introduce simple functions which help to know the on-going suspend mode so that other Xen-related code can behave differently according to the current suspend mode. Since Xen suspend doesn't have corresponding PM event, its main logic is modfied to acquire pm_mutex and set the current mode. Though, acquirng pm_mutex is still right thing to do, we may see deadlock if PM hibernation is interrupted by Xen suspend. PM hibernation depends on xenwatch thread to process xenbus state transactions, but the thread will sleep to wait pm_mutex which is already held by PM hibernation context in the scenario. Xen shutdown code may need some changes to avoid the issue. [Anchal Changelog: Merged patch xen/manage: introduce helper function to know the on-going suspend mode into this one for better readability] Signed-off-by: Anchal Agarwal Signed-off-by: Munehisa Kamata --- Changes since V2: None --- drivers/xen/manage.c | 73 +++++++++++++++++++++++++++++++++++++++++++ include/xen/xen-ops.h | 3 ++ 2 files changed, 76 insertions(+) diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c index cd046684e0d1..0b30ab522b77 100644 --- a/drivers/xen/manage.c +++ b/drivers/xen/manage.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include @@ -40,6 +41,31 @@ enum shutdown_state { /* Ignore multiple shutdown requests. */ static enum shutdown_state shutting_down = SHUTDOWN_INVALID; +enum suspend_modes { + NO_SUSPEND = 0, + XEN_SUSPEND, + PM_SUSPEND, + PM_HIBERNATION, +}; + +/* Protected by pm_mutex */ +static enum suspend_modes suspend_mode = NO_SUSPEND; + +bool xen_suspend_mode_is_xen_suspend(void) +{ + return suspend_mode == XEN_SUSPEND; +} + +bool xen_suspend_mode_is_pm_suspend(void) +{ + return suspend_mode == PM_SUSPEND; +} + +bool xen_suspend_mode_is_pm_hibernation(void) +{ + return suspend_mode == PM_HIBERNATION; +} + struct suspend_info { int cancelled; }; @@ -99,6 +125,10 @@ static void do_suspend(void) int err; struct suspend_info si; + lock_system_sleep(); + + suspend_mode = XEN_SUSPEND; + shutting_down = SHUTDOWN_SUSPEND; err = freeze_processes(); @@ -162,6 +192,10 @@ static void do_suspend(void) thaw_processes(); out: shutting_down = SHUTDOWN_INVALID; + + suspend_mode = NO_SUSPEND; + + unlock_system_sleep(); } #endif /* CONFIG_HIBERNATE_CALLBACKS */ @@ -387,3 +421,42 @@ int xen_setup_shutdown_event(void) EXPORT_SYMBOL_GPL(xen_setup_shutdown_event); subsys_initcall(xen_setup_shutdown_event); + +static int xen_pm_notifier(struct notifier_block *notifier, + unsigned long pm_event, void *unused) +{ + switch (pm_event) { + case PM_SUSPEND_PREPARE: + suspend_mode = PM_SUSPEND; + break; + case PM_HIBERNATION_PREPARE: + case PM_RESTORE_PREPARE: + suspend_mode = PM_HIBERNATION; + break; + case PM_POST_SUSPEND: + case PM_POST_RESTORE: + case PM_POST_HIBERNATION: + /* Set back to the default */ + suspend_mode = NO_SUSPEND; + break; + default: + pr_warn("Receive unknown PM event 0x%lx\n", pm_event); + return -EINVAL; + } + + return 0; +}; + +static struct notifier_block xen_pm_notifier_block = { + .notifier_call = xen_pm_notifier +}; + +static int xen_setup_pm_notifier(void) +{ + if (!xen_hvm_domain()) + return -ENODEV; + + return register_pm_notifier(&xen_pm_notifier_block); +} + +subsys_initcall(xen_setup_pm_notifier); diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h index d89969aa9942..6c36e161dfd1 100644 --- a/include/xen/xen-ops.h +++ b/include/xen/xen-ops.h @@ -40,6 +40,9 @@ u64 xen_steal_clock(int cpu); int xen_setup_shutdown_event(void); +bool xen_suspend_mode_is_xen_suspend(void); +bool xen_suspend_mode_is_pm_suspend(void); +bool xen_suspend_mode_is_pm_hibernation(void); extern unsigned long *xen_contiguous_bitmap; #if defined(CONFIG_XEN_PV) || defined(CONFIG_ARM) || defined(CONFIG_ARM64) From patchwork Wed Feb 12 22:30:41 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anchal Agarwal X-Patchwork-Id: 11379257 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 036ED1805 for ; Wed, 12 Feb 2020 22:31:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE37221739 for ; Wed, 12 Feb 2020 22:31:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="W4UpfbIr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729133AbgBLWbS (ORCPT ); Wed, 12 Feb 2020 17:31:18 -0500 Received: from smtp-fw-4101.amazon.com ([72.21.198.25]:13530 "EHLO smtp-fw-4101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727564AbgBLWbS (ORCPT ); Wed, 12 Feb 2020 17:31:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1581546677; x=1613082677; h=date:from:to:subject:message-id:mime-version; bh=i32EpGwooPZB678+D/0hzPuRDA1ywUkOMkk4sBBTlvc=; b=W4UpfbIrD/yGFPpDHOkc3MjBOeL62CFImeFLF1szsk/RWA05jzmNmpgp g+mnwmtYV1Wmmu9QfPge/W6QZBFi5MJTnhCH90788PJ9WigX0BVWrtTRC PM//D1zdLt+KagdA5l3emH+p/T5deeXDYNScVlULr9NESZFx3XiDz4ZUm Q=; IronPort-SDR: qn2VCGL67F8NU6wHmD7uN4NTt1lAzS4kjoxt6t2Mmjy3qyK1SegDvIKuhhwGlsKxrbuCXMqUQs nNRiMn5MMHhg== X-IronPort-AV: E=Sophos;i="5.70,434,1574121600"; d="scan'208";a="16853770" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-2b-c300ac87.us-west-2.amazon.com) ([10.43.8.6]) by smtp-border-fw-out-4101.iad4.amazon.com with ESMTP; 12 Feb 2020 22:31:02 +0000 Received: from EX13MTAUEE002.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan2.pdx.amazon.com [10.170.41.162]) by email-inbound-relay-2b-c300ac87.us-west-2.amazon.com (Postfix) with ESMTPS id 5F065A2708; Wed, 12 Feb 2020 22:31:00 +0000 (UTC) Received: from EX13D08UEE001.ant.amazon.com (10.43.62.126) by EX13MTAUEE002.ant.amazon.com (10.43.62.24) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:30:41 +0000 Received: from EX13MTAUEE002.ant.amazon.com (10.43.62.24) by EX13D08UEE001.ant.amazon.com (10.43.62.126) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:30:42 +0000 Received: from dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (172.22.96.68) by mail-relay.amazon.com (10.43.62.224) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Wed, 12 Feb 2020 22:30:41 +0000 Received: by dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (Postfix, from userid 4335130) id A365E400D1; Wed, 12 Feb 2020 22:30:41 +0000 (UTC) Date: Wed, 12 Feb 2020 22:30:41 +0000 From: Anchal Agarwal To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [RFC PATCH v3 02/12] xenbus: add freeze/thaw/restore callbacks support Message-ID: <20200212223041.GA3597@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Munehisa Kamata Since commit b3e96c0c7562 ("xen: use freeze/restore/thaw PM events for suspend/resume/chkpt"), xenbus uses PMSG_FREEZE, PMSG_THAW and PMSG_RESTORE events for Xen suspend. However, they're actually assigned to xenbus_dev_suspend(), xenbus_dev_cancel() and xenbus_dev_resume() respectively, and only suspend and resume callbacks are supported at driver level. To support PM suspend and PM hibernation, modify the bus level PM callbacks to invoke not only device driver's suspend/resume but also freeze/thaw/restore. Note that we'll use freeze/restore callbacks even for PM suspend whereas suspend/resume callbacks are normally used in the case, becausae the existing xenbus device drivers already have suspend/resume callbacks specifically designed for Xen suspend. So we can allow the device drivers to keep the existing callbacks wihtout modification. [Anchal Changelog: Refactored the callbacks code] Signed-off-by: Agarwal Anchal Signed-off-by: Munehisa Kamata --- Changes since V2: None --- drivers/xen/xenbus/xenbus_probe.c | 99 +++++++++++++++++++++++++------ include/xen/xenbus.h | 3 + 2 files changed, 84 insertions(+), 18 deletions(-) diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c index 5b471889d723..0fa8eeee68c2 100644 --- a/drivers/xen/xenbus/xenbus_probe.c +++ b/drivers/xen/xenbus/xenbus_probe.c @@ -49,6 +49,7 @@ #include #include #include +#include #include #include @@ -597,27 +598,44 @@ int xenbus_dev_suspend(struct device *dev) struct xenbus_driver *drv; struct xenbus_device *xdev = container_of(dev, struct xenbus_device, dev); - + bool xen_suspend = xen_suspend_mode_is_xen_suspend(); DPRINTK("%s", xdev->nodename); if (dev->driver == NULL) return 0; drv = to_xenbus_driver(dev->driver); - if (drv->suspend) - err = drv->suspend(xdev); - if (err) - pr_warn("suspend %s failed: %i\n", dev_name(dev), err); + + if (xen_suspend) { + if (drv->suspend) + err = drv->suspend(xdev); + } else { + if (drv->freeze) { + err = drv->freeze(xdev); + if (!err) { + free_otherend_watch(xdev); + free_otherend_details(xdev); + return 0; + } + } + } + + if (err) { + pr_warn("%s %s failed: %i\n", xen_suspend ? + "suspend" : "freeze", dev_name(dev), err); + return err; + } + return 0; } EXPORT_SYMBOL_GPL(xenbus_dev_suspend); int xenbus_dev_resume(struct device *dev) { - int err; + int err = 0; struct xenbus_driver *drv; struct xenbus_device *xdev = container_of(dev, struct xenbus_device, dev); - + bool xen_suspend = xen_suspend_mode_is_xen_suspend(); DPRINTK("%s", xdev->nodename); if (dev->driver == NULL) @@ -625,24 +643,32 @@ int xenbus_dev_resume(struct device *dev) drv = to_xenbus_driver(dev->driver); err = talk_to_otherend(xdev); if (err) { - pr_warn("resume (talk_to_otherend) %s failed: %i\n", + pr_warn("%s (talk_to_otherend) %s failed: %i\n", + xen_suspend ? "resume" : "restore", dev_name(dev), err); return err; } - xdev->state = XenbusStateInitialising; + if (xen_suspend) { + xdev->state = XenbusStateInitialising; + if (drv->resume) + err = drv->resume(xdev); + } else { + if (drv->restore) + err = drv->restore(xdev); + } - if (drv->resume) { - err = drv->resume(xdev); - if (err) { - pr_warn("resume %s failed: %i\n", dev_name(dev), err); - return err; - } + if (err) { + pr_warn("%s %s failed: %i\n", + xen_suspend ? "resume" : "restore", + dev_name(dev), err); + return err; } err = watch_otherend(xdev); if (err) { - pr_warn("resume (watch_otherend) %s failed: %d.\n", + pr_warn("%s (watch_otherend) %s failed: %d.\n", + xen_suspend ? "resume" : "restore", dev_name(dev), err); return err; } @@ -653,8 +679,45 @@ EXPORT_SYMBOL_GPL(xenbus_dev_resume); int xenbus_dev_cancel(struct device *dev) { - /* Do nothing */ - DPRINTK("cancel"); + int err = 0; + struct xenbus_driver *drv; + struct xenbus_device *xdev + = container_of(dev, struct xenbus_device, dev); + bool xen_suspend = xen_suspend_mode_is_xen_suspend(); + + if (xen_suspend) { + /* Do nothing */ + DPRINTK("cancel"); + return 0; + } + + DPRINTK("%s", xdev->nodename); + + if (dev->driver == NULL) + return 0; + drv = to_xenbus_driver(dev->driver); + err = talk_to_otherend(xdev); + if (err) { + pr_warn("thaw (talk_to_otherend) %s failed: %d.\n", + dev_name(dev), err); + return err; + } + + if (drv->thaw) { + err = drv->thaw(xdev); + if (err) { + pr_warn("thaw %s failed: %i\n", dev_name(dev), err); + return err; + } + } + + err = watch_otherend(xdev); + if (err) { + pr_warn("thaw (watch_otherend) %s failed: %d.\n", + dev_name(dev), err); + return err; + } + return 0; } EXPORT_SYMBOL_GPL(xenbus_dev_cancel); diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h index 869c816d5f8c..20261d5f4e78 100644 --- a/include/xen/xenbus.h +++ b/include/xen/xenbus.h @@ -100,6 +100,9 @@ struct xenbus_driver { int (*remove)(struct xenbus_device *dev); int (*suspend)(struct xenbus_device *dev); int (*resume)(struct xenbus_device *dev); + int (*freeze)(struct xenbus_device *dev); + int (*thaw)(struct xenbus_device *dev); + int (*restore)(struct xenbus_device *dev); int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *); struct device_driver driver; int (*read_otherend_details)(struct xenbus_device *dev); From patchwork Wed Feb 12 22:31:34 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anchal Agarwal X-Patchwork-Id: 11379265 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E08BE14E3 for ; Wed, 12 Feb 2020 22:32:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BD5EA21739 for ; Wed, 12 Feb 2020 22:32:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="BD/VBWFg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727947AbgBLWcN (ORCPT ); Wed, 12 Feb 2020 17:32:13 -0500 Received: from smtp-fw-6001.amazon.com ([52.95.48.154]:27956 "EHLO smtp-fw-6001.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727692AbgBLWcN (ORCPT ); Wed, 12 Feb 2020 17:32:13 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1581546732; x=1613082732; h=date:from:to:subject:message-id:mime-version; bh=ripc5+9/gE+qNPNBav/IIcm5ONNdq1mgToxmDX/jFW0=; b=BD/VBWFgh88GB7S74RQOCBRf77hdGKWMkusuYt9uZveDwI62KNBY0CYb ev9SonLhNh1xN8+DDV6iNaegEihEgyzsFRnSFESM3QFLyDbAu+Xd2vUF8 6XwQ/1x1DjIW1pHzYud8lI7U2aEGNDb6hfLjzCyl81RMJl5/nlLmL0u7e A=; IronPort-SDR: gWdTJ5PKnY7douCc4vbbNcXx94KDrgyfXSO+Z9w6LtPWXGYkzF7Gj3MVWjoq7H58a0vZhfHqJE 3M+L5XR+QY3g== X-IronPort-AV: E=Sophos;i="5.70,434,1574121600"; d="scan'208";a="17479331" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-2c-2225282c.us-west-2.amazon.com) ([10.43.8.6]) by smtp-border-fw-out-6001.iad6.amazon.com with ESMTP; 12 Feb 2020 22:31:57 +0000 Received: from EX13MTAUEE002.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan3.pdx.amazon.com [10.170.41.166]) by email-inbound-relay-2c-2225282c.us-west-2.amazon.com (Postfix) with ESMTPS id 09736A2725; Wed, 12 Feb 2020 22:31:55 +0000 (UTC) Received: from EX13D08UEE003.ant.amazon.com (10.43.62.118) by EX13MTAUEE002.ant.amazon.com (10.43.62.24) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:31:35 +0000 Received: from EX13MTAUEA002.ant.amazon.com (10.43.61.77) by EX13D08UEE003.ant.amazon.com (10.43.62.118) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:31:35 +0000 Received: from dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (172.22.96.68) by mail-relay.amazon.com (10.43.61.169) with Microsoft SMTP Server id 15.0.1236.3 via Frontend Transport; Wed, 12 Feb 2020 22:31:35 +0000 Received: by dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (Postfix, from userid 4335130) id DBCC2400D1; Wed, 12 Feb 2020 22:31:34 +0000 (UTC) Date: Wed, 12 Feb 2020 22:31:34 +0000 From: Anchal Agarwal To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [RFC PATCH v3 03/12] x86/xen: Introduce new function to map HYPERVISOR_shared_info on Resume Message-ID: <20200212223134.GA3625@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Introduce a small function which re-uses shared page's PA allocated during guest initialization time in reserve_shared_info() and not allocate new page during resume flow. It also does the mapping of shared_info_page by calling xen_hvm_init_shared_info() to use the function. Signed-off-by: Anchal Agarwal --- Changes since V2: None --- arch/x86/xen/enlighten_hvm.c | 7 +++++++ arch/x86/xen/xen-ops.h | 1 + 2 files changed, 8 insertions(+) diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c index e138f7de52d2..75b1ec7a0fcd 100644 --- a/arch/x86/xen/enlighten_hvm.c +++ b/arch/x86/xen/enlighten_hvm.c @@ -27,6 +27,13 @@ static unsigned long shared_info_pfn; +void xen_hvm_map_shared_info(void) +{ + xen_hvm_init_shared_info(); + if (shared_info_pfn) + HYPERVISOR_shared_info = __va(PFN_PHYS(shared_info_pfn)); +} + void xen_hvm_init_shared_info(void) { struct xen_add_to_physmap xatp; diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index 45a441c33d6d..d84c357994bd 100644 --- a/arch/x86/xen/xen-ops.h +++ b/arch/x86/xen/xen-ops.h @@ -56,6 +56,7 @@ void xen_enable_syscall(void); void xen_vcpu_restore(void); void xen_callback_vector(void); +void xen_hvm_map_shared_info(void); void xen_hvm_init_shared_info(void); void xen_unplug_emulated_devices(void); From patchwork Wed Feb 12 22:32:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anchal Agarwal X-Patchwork-Id: 11379271 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 75F0C921 for ; Wed, 12 Feb 2020 22:32:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4BD4624649 for ; Wed, 12 Feb 2020 22:32:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="bTV+6D7x" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729157AbgBLWcj (ORCPT ); Wed, 12 Feb 2020 17:32:39 -0500 Received: from smtp-fw-33001.amazon.com ([207.171.190.10]:19456 "EHLO smtp-fw-33001.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727692AbgBLWcj (ORCPT ); Wed, 12 Feb 2020 17:32:39 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1581546758; x=1613082758; h=date:from:to:subject:message-id:mime-version; bh=+zXTnUkKMKFgalRZdwxTzRNR5GJFShLVu/RYZfBNJ1E=; b=bTV+6D7xYgf4WMFiUNc1JKH/pUztJ98EkU3NF5RlK42bWsLedr6mbODB WE+CgvDp/BEbacnpC5He9PZlheL+JNHBe5QLYgJyfFZ+KCWFCqbVRNtr9 3XfyuBydk1PBBIPbUwJfwcmVNYbdEN3VgDRRVR3YCJ9s2yPy4BijfMWFV c=; IronPort-SDR: 77EBN9MgMbUwDv9LWl4gOIf/QNV8FXtGYDzmsxpHs1JZq+U748pBK+5Sy5PmhtEG6P6qMcuEDc 460r1jycdjLg== X-IronPort-AV: E=Sophos;i="5.70,434,1574121600"; d="scan'208";a="26088733" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-1d-38ae4ad2.us-east-1.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-33001.sea14.amazon.com with ESMTP; 12 Feb 2020 22:32:34 +0000 Received: from EX13MTAUWA001.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan3.iad.amazon.com [10.40.159.166]) by email-inbound-relay-1d-38ae4ad2.us-east-1.amazon.com (Postfix) with ESMTPS id 8A604A219B; Wed, 12 Feb 2020 22:32:27 +0000 (UTC) Received: from EX13D01UWA002.ant.amazon.com (10.43.160.74) by EX13MTAUWA001.ant.amazon.com (10.43.160.58) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:32:08 +0000 Received: from EX13MTAUWA001.ant.amazon.com (10.43.160.58) by EX13d01UWA002.ant.amazon.com (10.43.160.74) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 12 Feb 2020 22:32:07 +0000 Received: from dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (172.22.96.68) by mail-relay.amazon.com (10.43.160.118) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Wed, 12 Feb 2020 22:32:07 +0000 Received: by dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (Postfix, from userid 4335130) id 805CC400D1; Wed, 12 Feb 2020 22:32:07 +0000 (UTC) Date: Wed, 12 Feb 2020 22:32:07 +0000 From: Anchal Agarwal To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [RFC PATCH v3 05/12] xen-netfront: add callbacks for PM suspend and hibernation support Message-ID: <20200212223207.GA4169@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Munehisa Kamata Add freeze, thaw and restore callbacks for PM suspend and hibernation support. The freeze handler simply disconnects the frotnend from the backend and frees resources associated with queues after disabling the net_device from the system. The restore handler just changes the frontend state and let the xenbus handler to re-allocate the resources and re-connect to the backend. This can be performed transparently to the rest of the system. The handlers are used for both PM suspend and hibernation so that we can keep the existing suspend/resume callbacks for Xen suspend without modification. Freezing netfront devices is normally expected to finish within a few hundred milliseconds, but it can rarely take more than 5 seconds and hit the hard coded timeout, it would depend on backend state which may be congested and/or have complex configuration. While it's rare case, longer default timeout seems a bit more reasonable here to avoid hitting the timeout. Also, make it configurable via module parameter so that we can cover broader setups than what we know currently. [Anchal changelog: Variable name fix and checkpatch.pl fixes] Signed-off-by: Anchal Agarwal Signed-off-by: Munehisa Kamata --- Changes since V2: None --- drivers/net/xen-netfront.c | 98 +++++++++++++++++++++++++++++++++++++- 1 file changed, 97 insertions(+), 1 deletion(-) diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 482c6c8b0fb7..65edcdd6e05f 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -43,6 +43,7 @@ #include #include #include +#include #include #include @@ -56,6 +57,12 @@ #include #include +enum netif_freeze_state { + NETIF_FREEZE_STATE_UNFROZEN, + NETIF_FREEZE_STATE_FREEZING, + NETIF_FREEZE_STATE_FROZEN, +}; + /* Module parameters */ #define MAX_QUEUES_DEFAULT 8 static unsigned int xennet_max_queues; @@ -63,6 +70,12 @@ module_param_named(max_queues, xennet_max_queues, uint, 0644); MODULE_PARM_DESC(max_queues, "Maximum number of queues per virtual interface"); +static unsigned int netfront_freeze_timeout_secs = 10; +module_param_named(freeze_timeout_secs, + netfront_freeze_timeout_secs, uint, 0644); +MODULE_PARM_DESC(freeze_timeout_secs, + "timeout when freezing netfront device in seconds"); + static const struct ethtool_ops xennet_ethtool_ops; struct netfront_cb { @@ -160,6 +173,10 @@ struct netfront_info { struct netfront_stats __percpu *tx_stats; atomic_t rx_gso_checksum_fixup; + + int freeze_state; + + struct completion wait_backend_disconnected; }; struct netfront_rx_info { @@ -721,6 +738,21 @@ static int xennet_close(struct net_device *dev) return 0; } +static int xennet_disable_interrupts(struct net_device *dev) +{ + struct netfront_info *np = netdev_priv(dev); + unsigned int num_queues = dev->real_num_tx_queues; + unsigned int queue_index; + struct netfront_queue *queue; + + for (queue_index = 0; queue_index < num_queues; ++queue_index) { + queue = &np->queues[queue_index]; + disable_irq(queue->tx_irq); + disable_irq(queue->rx_irq); + } + return 0; +} + static void xennet_move_rx_slot(struct netfront_queue *queue, struct sk_buff *skb, grant_ref_t ref) { @@ -1301,6 +1333,8 @@ static struct net_device *xennet_create_dev(struct xenbus_device *dev) np->queues = NULL; + init_completion(&np->wait_backend_disconnected); + err = -ENOMEM; np->rx_stats = netdev_alloc_pcpu_stats(struct netfront_stats); if (np->rx_stats == NULL) @@ -1794,6 +1828,50 @@ static int xennet_create_queues(struct netfront_info *info, return 0; } +static int netfront_freeze(struct xenbus_device *dev) +{ + struct netfront_info *info = dev_get_drvdata(&dev->dev); + unsigned long timeout = netfront_freeze_timeout_secs * HZ; + int err = 0; + + xennet_disable_interrupts(info->netdev); + + netif_device_detach(info->netdev); + + info->freeze_state = NETIF_FREEZE_STATE_FREEZING; + + /* Kick the backend to disconnect */ + xenbus_switch_state(dev, XenbusStateClosing); + + /* We don't want to move forward before the frontend is diconnected + * from the backend cleanly. + */ + timeout = wait_for_completion_timeout(&info->wait_backend_disconnected, + timeout); + if (!timeout) { + err = -EBUSY; + xenbus_dev_error(dev, err, "Freezing timed out;" + "the device may become inconsistent state"); + return err; + } + + /* Tear down queues */ + xennet_disconnect_backend(info); + xennet_destroy_queues(info); + + info->freeze_state = NETIF_FREEZE_STATE_FROZEN; + + return err; +} + +static int netfront_restore(struct xenbus_device *dev) +{ + /* Kick the backend to re-connect */ + xenbus_switch_state(dev, XenbusStateInitialising); + + return 0; +} + /* Common code used when first setting up, and when resuming. */ static int talk_to_netback(struct xenbus_device *dev, struct netfront_info *info) @@ -1999,6 +2077,8 @@ static int xennet_connect(struct net_device *dev) spin_unlock_bh(&queue->rx_lock); } + np->freeze_state = NETIF_FREEZE_STATE_UNFROZEN; + return 0; } @@ -2036,10 +2116,23 @@ static void netback_changed(struct xenbus_device *dev, break; case XenbusStateClosed: - if (dev->state == XenbusStateClosed) + if (dev->state == XenbusStateClosed) { + /* dpm context is waiting for the backend */ + if (np->freeze_state == NETIF_FREEZE_STATE_FREEZING) + complete(&np->wait_backend_disconnected); break; + } + /* Fall through - Missed the backend's CLOSING state. */ case XenbusStateClosing: + /* We may see unexpected Closed or Closing from the backend. + * Just ignore it not to prevent the frontend from being + * re-connected in the case of PM suspend or hibernation. + */ + if (np->freeze_state == NETIF_FREEZE_STATE_FROZEN && + dev->state == XenbusStateInitialising) { + break; + } xenbus_frontend_closed(dev); break; } @@ -2186,6 +2279,9 @@ static struct xenbus_driver netfront_driver = { .probe = netfront_probe, .remove = xennet_remove, .resume = netfront_resume, + .freeze = netfront_freeze, + .thaw = netfront_restore, + .restore = netfront_restore, .otherend_changed = netback_changed, }; From patchwork Wed Feb 12 22:32:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anchal Agarwal X-Patchwork-Id: 11379281 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8B094921 for ; Wed, 12 Feb 2020 22:33:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 56B2424677 for ; Wed, 12 Feb 2020 22:33:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="NBGnRPZE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727692AbgBLWdG (ORCPT ); Wed, 12 Feb 2020 17:33:06 -0500 Received: from smtp-fw-2101.amazon.com ([72.21.196.25]:21121 "EHLO smtp-fw-2101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727564AbgBLWdG (ORCPT ); Wed, 12 Feb 2020 17:33:06 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1581546786; x=1613082786; h=date:from:to:subject:message-id:mime-version; bh=Li7ZytGzpLPeaAtxK4UWxJ/i7dWzVa/JFI81RD45Jfo=; b=NBGnRPZEE9Hh6fVnSyRa4p3GLr7fE2f/+cX/BMQynJ0fhFBS/nEYQ77P rHE+yMbCEmWrT4Eq/dot/8OjgeR6AF9GJFmS0OsJz0y1Jeal9nX+U4g4r s0tPWBpGZ5D+C7ykH0YXqLUyTmi14GmxDQ6rE8sPmK9WVfyALYuYL2m+y I=; IronPort-SDR: aTjsW3zj+x0uHsppmlnRsOirp4sS2hT7wHd0CjS3hdVl3ldpWv54Plk3oV0dFj27SEC1MWlkE8 saMAZwY+vejw== X-IronPort-AV: E=Sophos;i="5.70,434,1574121600"; d="scan'208";a="16933191" Received: from iad12-co-svc-p1-lb1-vlan2.amazon.com (HELO email-inbound-relay-1a-807d4a99.us-east-1.amazon.com) ([10.43.8.2]) by smtp-border-fw-out-2101.iad2.amazon.com with ESMTP; 12 Feb 2020 22:33:06 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan2.iad.amazon.com [10.40.159.162]) by email-inbound-relay-1a-807d4a99.us-east-1.amazon.com (Postfix) with ESMTPS id 45C21A2FDF; Wed, 12 Feb 2020 22:32:57 +0000 (UTC) Received: from EX13D07UWB001.ant.amazon.com (10.43.161.238) by EX13MTAUWB001.ant.amazon.com (10.43.161.249) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:32:37 +0000 Received: from EX13MTAUWB001.ant.amazon.com (10.43.161.207) by EX13D07UWB001.ant.amazon.com (10.43.161.238) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:32:37 +0000 Received: from dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (172.22.96.68) by mail-relay.amazon.com (10.43.161.249) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Wed, 12 Feb 2020 22:32:37 +0000 Received: by dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (Postfix, from userid 4335130) id 18453400D1; Wed, 12 Feb 2020 22:32:37 +0000 (UTC) Date: Wed, 12 Feb 2020 22:32:37 +0000 From: Anchal Agarwal To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [RFC PATCH v3 06/12] xen-blkfront: add callbacks for PM suspend and hibernation Message-ID: <20200212223237.GA4238@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Munehisa Kamata Add freeze, thaw and restore callbacks for PM suspend and hibernation support. All frontend drivers that needs to use PM_HIBERNATION/PM_SUSPEND events, need to implement these xenbus_driver callbacks. The freeze handler stops a block-layer queue and disconnect the frontend from the backend while freeing ring_info and associated resources. The restore handler re-allocates ring_info and re-connect to the backend, so the rest of the kernel can continue to use the block device transparently. Also, the handlers are used for both PM suspend and hibernation so that we can keep the existing suspend/resume callbacks for Xen suspend without modification. Before disconnecting from backend, we need to prevent any new IO from being queued and wait for existing IO to complete. Freeze/unfreeze of the queues will guarantee that there are no requests in use on the shared ring. Note:For older backends,if a backend doesn't have commit'12ea729645ace' xen/blkback: unmap all persistent grants when frontend gets disconnected, the frontend may see massive amount of grant table warning when freeing resources. [ 36.852659] deferring g.e. 0xf9 (pfn 0xffffffffffffffff) [ 36.855089] xen:grant_table: WARNING:e.g. 0x112 still in use! In this case, persistent grants would need to be disabled. [Anchal Changelog: Removed timeout/request during blkfront freeze. Fixed major part of the code to work with blk-mq] Signed-off-by: Anchal Agarwal Signed-off-by: Munehisa Kamata --- Changes since V2: None --- drivers/block/xen-blkfront.c | 119 ++++++++++++++++++++++++++++++++--- 1 file changed, 112 insertions(+), 7 deletions(-) diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 478120233750..d715ed3cb69a 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -47,6 +47,8 @@ #include #include #include +#include +#include #include #include @@ -79,6 +81,8 @@ enum blkif_state { BLKIF_STATE_DISCONNECTED, BLKIF_STATE_CONNECTED, BLKIF_STATE_SUSPENDED, + BLKIF_STATE_FREEZING, + BLKIF_STATE_FROZEN }; struct grant { @@ -220,6 +224,7 @@ struct blkfront_info struct list_head requests; struct bio_list bio_list; struct list_head info_list; + struct completion wait_backend_disconnected; }; static unsigned int nr_minors; @@ -261,6 +266,7 @@ static DEFINE_SPINLOCK(minor_lock); static int blkfront_setup_indirect(struct blkfront_ring_info *rinfo); static void blkfront_gather_backend_features(struct blkfront_info *info); static int negotiate_mq(struct blkfront_info *info); +static void __blkif_free(struct blkfront_info *info); static int get_id_from_freelist(struct blkfront_ring_info *rinfo) { @@ -995,6 +1001,7 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size, info->sector_size = sector_size; info->physical_sector_size = physical_sector_size; blkif_set_queue_limits(info); + init_completion(&info->wait_backend_disconnected); return 0; } @@ -1218,6 +1225,8 @@ static void xlvbd_release_gendisk(struct blkfront_info *info) /* Already hold rinfo->ring_lock. */ static inline void kick_pending_request_queues_locked(struct blkfront_ring_info *rinfo) { + if (unlikely(rinfo->dev_info->connected == BLKIF_STATE_FREEZING)) + return; if (!RING_FULL(&rinfo->ring)) blk_mq_start_stopped_hw_queues(rinfo->dev_info->rq, true); } @@ -1341,8 +1350,6 @@ static void blkif_free_ring(struct blkfront_ring_info *rinfo) static void blkif_free(struct blkfront_info *info, int suspend) { - unsigned int i; - /* Prevent new requests being issued until we fix things up. */ info->connected = suspend ? BLKIF_STATE_SUSPENDED : BLKIF_STATE_DISCONNECTED; @@ -1350,6 +1357,13 @@ static void blkif_free(struct blkfront_info *info, int suspend) if (info->rq) blk_mq_stop_hw_queues(info->rq); + __blkif_free(info); +} + +static void __blkif_free(struct blkfront_info *info) +{ + unsigned int i; + for (i = 0; i < info->nr_rings; i++) blkif_free_ring(&info->rinfo[i]); @@ -1553,8 +1567,10 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id) struct blkfront_ring_info *rinfo = (struct blkfront_ring_info *)dev_id; struct blkfront_info *info = rinfo->dev_info; - if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) - return IRQ_HANDLED; + if (unlikely(info->connected != BLKIF_STATE_CONNECTED)) { + if (info->connected != BLKIF_STATE_FREEZING) + return IRQ_HANDLED; + } spin_lock_irqsave(&rinfo->ring_lock, flags); again: @@ -2020,6 +2036,7 @@ static int blkif_recover(struct blkfront_info *info) struct bio *bio; unsigned int segs; + bool frozen = info->connected == BLKIF_STATE_FROZEN; blkfront_gather_backend_features(info); /* Reset limits changed by blk_mq_update_nr_hw_queues(). */ blkif_set_queue_limits(info); @@ -2046,6 +2063,9 @@ static int blkif_recover(struct blkfront_info *info) kick_pending_request_queues(rinfo); } + if (frozen) + return 0; + list_for_each_entry_safe(req, n, &info->requests, queuelist) { /* Requeue pending requests (flush or discard) */ list_del_init(&req->queuelist); @@ -2359,6 +2379,7 @@ static void blkfront_connect(struct blkfront_info *info) return; case BLKIF_STATE_SUSPENDED: + case BLKIF_STATE_FROZEN: /* * If we are recovering from suspension, we need to wait * for the backend to announce it's features before @@ -2476,12 +2497,37 @@ static void blkback_changed(struct xenbus_device *dev, break; case XenbusStateClosed: - if (dev->state == XenbusStateClosed) + if (dev->state == XenbusStateClosed) { + if (info->connected == BLKIF_STATE_FREEZING) { + __blkif_free(info); + info->connected = BLKIF_STATE_FROZEN; + complete(&info->wait_backend_disconnected); + break; + } + break; + } + + /* + * We may somehow receive backend's Closed again while thawing + * or restoring and it causes thawing or restoring to fail. + * Ignore such unexpected state anyway. + */ + if (info->connected == BLKIF_STATE_FROZEN && + dev->state == XenbusStateInitialised) { + dev_dbg(&dev->dev, + "ignore the backend's Closed state: %s", + dev->nodename); + break; + } /* fall through */ case XenbusStateClosing: - if (info) - blkfront_closing(info); + if (info) { + if (info->connected == BLKIF_STATE_FREEZING) + xenbus_frontend_closed(dev); + else + blkfront_closing(info); + } break; } } @@ -2625,6 +2671,62 @@ static void blkif_release(struct gendisk *disk, fmode_t mode) mutex_unlock(&blkfront_mutex); } +static int blkfront_freeze(struct xenbus_device *dev) +{ + unsigned int i; + struct blkfront_info *info = dev_get_drvdata(&dev->dev); + struct blkfront_ring_info *rinfo; + /* This would be reasonable timeout as used in xenbus_dev_shutdown() */ + unsigned int timeout = 5 * HZ; + int err = 0; + + info->connected = BLKIF_STATE_FREEZING; + + blk_mq_freeze_queue(info->rq); + blk_mq_quiesce_queue(info->rq); + + for (i = 0; i < info->nr_rings; i++) { + rinfo = &info->rinfo[i]; + + gnttab_cancel_free_callback(&rinfo->callback); + flush_work(&rinfo->work); + } + + /* Kick the backend to disconnect */ + xenbus_switch_state(dev, XenbusStateClosing); + + /* + * We don't want to move forward before the frontend is diconnected + * from the backend cleanly. + */ + timeout = wait_for_completion_timeout(&info->wait_backend_disconnected, + timeout); + if (!timeout) { + err = -EBUSY; + xenbus_dev_error(dev, err, "Freezing timed out;" + "the device may become inconsistent state"); + } + + return err; +} + +static int blkfront_restore(struct xenbus_device *dev) +{ + struct blkfront_info *info = dev_get_drvdata(&dev->dev); + int err = 0; + + err = talk_to_blkback(dev, info); + blk_mq_unquiesce_queue(info->rq); + blk_mq_unfreeze_queue(info->rq); + + if (err) + goto out; + blk_mq_update_nr_hw_queues(&info->tag_set, info->nr_rings); + +out: + return err; +} + static const struct block_device_operations xlvbd_block_fops = { .owner = THIS_MODULE, @@ -2647,6 +2749,9 @@ static struct xenbus_driver blkfront_driver = { .resume = blkfront_resume, .otherend_changed = blkback_changed, .is_ready = blkfront_is_ready, + .freeze = blkfront_freeze, + .thaw = blkfront_restore, + .restore = blkfront_restore }; static void purge_persistent_grants(struct blkfront_info *info) From patchwork Wed Feb 12 22:33:04 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anchal Agarwal X-Patchwork-Id: 11379285 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9877D921 for ; Wed, 12 Feb 2020 22:33:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6DA2F21739 for ; Wed, 12 Feb 2020 22:33:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="oo6cXdKE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729125AbgBLWdk (ORCPT ); Wed, 12 Feb 2020 17:33:40 -0500 Received: from smtp-fw-6002.amazon.com ([52.95.49.90]:14124 "EHLO smtp-fw-6002.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729103AbgBLWdj (ORCPT ); Wed, 12 Feb 2020 17:33:39 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1581546819; x=1613082819; h=date:from:to:subject:message-id:mime-version; bh=A9MU6ix5doEWHx0Vi3fmKI9vPHFZ3AdrseuapfeQP6E=; b=oo6cXdKExzZ42s6Pj6UB01pCDhsvV+KIwaI3YVMfxqkCUXvZmL7Ayp83 /+9H6nLd5NGJKxRqY9+zOZKpZWVUkZox5SPM9CARCdtTeXsRybXA5TfMN JMhMVvKQdoZWsSZVxddI3jd9b9T51SrGhFqMbi6K3hrQ9X18uqvWRbOdu I=; IronPort-SDR: 6SjWQm0/EyoJwJdeUjL93w2E+e0UXuq767GbG34KzQQlp+sr4MEOYRW+f62srQBgMnRa/xpbuQ pYbwJNMLtC2A== X-IronPort-AV: E=Sophos;i="5.70,434,1574121600"; d="scan'208";a="16031289" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-1d-5dd976cd.us-east-1.amazon.com) ([10.43.8.6]) by smtp-border-fw-out-6002.iad6.amazon.com with ESMTP; 12 Feb 2020 22:33:26 +0000 Received: from EX13MTAUEB002.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan3.iad.amazon.com [10.40.159.166]) by email-inbound-relay-1d-5dd976cd.us-east-1.amazon.com (Postfix) with ESMTPS id 9CF35A1F8F; Wed, 12 Feb 2020 22:33:19 +0000 (UTC) Received: from EX13D08UEB004.ant.amazon.com (10.43.60.142) by EX13MTAUEB002.ant.amazon.com (10.43.60.12) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:33:05 +0000 Received: from EX13MTAUEA001.ant.amazon.com (10.43.61.82) by EX13D08UEB004.ant.amazon.com (10.43.60.142) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:33:05 +0000 Received: from dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (172.22.96.68) by mail-relay.amazon.com (10.43.61.243) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Wed, 12 Feb 2020 22:33:04 +0000 Received: by dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (Postfix, from userid 4335130) id BFC29400D1; Wed, 12 Feb 2020 22:33:04 +0000 (UTC) Date: Wed, 12 Feb 2020 22:33:04 +0000 From: Anchal Agarwal To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [RFC PATCH v3 07/12] genirq: Shutdown irq chips in suspend/resume during hibernation Message-ID: <20200212223304.GA4262@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org There are no pm handlers for the legacy devices, so during tear down stale event channel <> IRQ mapping may still remain in the image and resume may fail. To avoid adding much code by implementing handlers for legacy devices, add a new irq_chip flag IRQCHIP_SHUTDOWN_ON_SUSPEND which when enabled on an irq-chip e.g xen-pirq, it will let core suspend/resume irq code to shutdown and restart the active irqs. PM suspend/hibernation code will rely on this. Without this, in PM hibernation, information about the event channel remains in hibernation image, but there is no guarantee that the same event channel numbers are assigned to the devices when restoring the system. This may cause conflict like the following and prevent some devices from being restored correctly. Signed-off-by: Anchal Agarwal Suggested-by: Thomas Gleixner --- Changes since V2: * Its new patch to fix shutdown/restore pirqs during hibernation * Removed previous 2 patches to shutdown/restore pirqs in xen code --- drivers/xen/events/events_base.c | 1 + include/linux/irq.h | 2 ++ kernel/irq/chip.c | 2 +- kernel/irq/internals.h | 1 + kernel/irq/pm.c | 31 ++++++++++++++++++++++--------- 5 files changed, 27 insertions(+), 10 deletions(-) diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index 6c8843968a52..e44f27b45bef 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -1620,6 +1620,7 @@ static struct irq_chip xen_pirq_chip __read_mostly = { .irq_set_affinity = set_affinity_irq, .irq_retrigger = retrigger_dynirq, + .flags = IRQCHIP_SHUTDOWN_ON_SUSPEND, }; static struct irq_chip xen_percpu_chip __read_mostly = { diff --git a/include/linux/irq.h b/include/linux/irq.h index fb301cf29148..2873a579fd9d 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -511,6 +511,7 @@ struct irq_chip { * IRQCHIP_EOI_THREADED: Chip requires eoi() on unmask in threaded mode * IRQCHIP_SUPPORTS_LEVEL_MSI Chip can provide two doorbells for Level MSIs * IRQCHIP_SUPPORTS_NMI: Chip can deliver NMIs, only for root irqchips + * IRQCHIP_SHUTDOWN_ON_SUSPEND: Shutdown non wake irqs in the suspend path */ enum { IRQCHIP_SET_TYPE_MASKED = (1 << 0), @@ -522,6 +523,7 @@ enum { IRQCHIP_EOI_THREADED = (1 << 6), IRQCHIP_SUPPORTS_LEVEL_MSI = (1 << 7), IRQCHIP_SUPPORTS_NMI = (1 << 8), + IRQCHIP_SHUTDOWN_ON_SUSPEND = (1 << 9), }; #include diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index b76703b2c0af..a1e8df5193ba 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -233,7 +233,7 @@ __irq_startup_managed(struct irq_desc *desc, struct cpumask *aff, bool force) } #endif -static int __irq_startup(struct irq_desc *desc) +int __irq_startup(struct irq_desc *desc) { struct irq_data *d = irq_desc_get_irq_data(desc); int ret = 0; diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h index 3924fbe829d4..11c7c55bda63 100644 --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -80,6 +80,7 @@ extern void __enable_irq(struct irq_desc *desc); extern int irq_activate(struct irq_desc *desc); extern int irq_activate_and_startup(struct irq_desc *desc, bool resend); extern int irq_startup(struct irq_desc *desc, bool resend, bool force); +extern int __irq_startup(struct irq_desc *desc); extern void irq_shutdown(struct irq_desc *desc); extern void irq_shutdown_and_deactivate(struct irq_desc *desc); diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c index 8f557fa1f4fe..dc48a25f1756 100644 --- a/kernel/irq/pm.c +++ b/kernel/irq/pm.c @@ -85,16 +85,25 @@ static bool suspend_device_irq(struct irq_desc *desc) } desc->istate |= IRQS_SUSPENDED; - __disable_irq(desc); - /* - * Hardware which has no wakeup source configuration facility - * requires that the non wakeup interrupts are masked at the - * chip level. The chip implementation indicates that with - * IRQCHIP_MASK_ON_SUSPEND. + * Some irq chips (e.g. XEN PIRQ) require a full shutdown on suspend + * as some of the legacy drivers(e.g. floppy) do nothing during the + * suspend path */ - if (irq_desc_get_chip(desc)->flags & IRQCHIP_MASK_ON_SUSPEND) - mask_irq(desc); + if (irq_desc_get_chip(desc)->flags & IRQCHIP_SHUTDOWN_ON_SUSPEND) { + irq_shutdown(desc); + } else { + __disable_irq(desc); + + /* + * Hardware which has no wakeup source configuration facility + * requires that the non wakeup interrupts are masked at the + * chip level. The chip implementation indicates that with + * IRQCHIP_MASK_ON_SUSPEND. + */ + if (irq_desc_get_chip(desc)->flags & IRQCHIP_MASK_ON_SUSPEND) + mask_irq(desc); + } return true; } @@ -152,7 +161,11 @@ static void resume_irq(struct irq_desc *desc) irq_state_set_masked(desc); resume: desc->istate &= ~IRQS_SUSPENDED; - __enable_irq(desc); + + if (irq_desc_get_chip(desc)->flags & IRQCHIP_SHUTDOWN_ON_SUSPEND) + __irq_startup(desc); + else + __enable_irq(desc); } static void resume_irqs(bool want_early) From patchwork Wed Feb 12 22:33:35 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anchal Agarwal X-Patchwork-Id: 11379291 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 852E2921 for ; Wed, 12 Feb 2020 22:34:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 598FD217F4 for ; Wed, 12 Feb 2020 22:34:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="tPn3ZqL+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728185AbgBLWeR (ORCPT ); Wed, 12 Feb 2020 17:34:17 -0500 Received: from smtp-fw-9102.amazon.com ([207.171.184.29]:21070 "EHLO smtp-fw-9102.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727947AbgBLWeR (ORCPT ); Wed, 12 Feb 2020 17:34:17 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1581546856; x=1613082856; h=date:from:to:subject:message-id:mime-version; bh=h6//YngfznNHckkx9Ke5t7SZWnTpuxZy2r6uPSfxRCE=; b=tPn3ZqL+1B2ulBs4TtC/x5igj99yJsK+o2s+GmDjgGvwtour6nmLwgsW Jx0K27NMKOof3dltvdloC8oEntTvXDgWlK92Uta2UlBQfR5PVnl2+qxYG v+3SkVfjXHIFmXoE7e/xrM6UsaywsHadR6VWDEEnwhMGlPDLWMQ6Lkc/I o=; IronPort-SDR: 2sE+e2jd+GGBElALb7Ph5Zz+ct1lsXDGX/PXq+AtmOqwAOaaSF/aeEOS4lmkGyqTdM+lQJLtnt f0+oC1hLM+lQ== X-IronPort-AV: E=Sophos;i="5.70,434,1574121600"; d="scan'208";a="24723164" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-1d-37fd6b3d.us-east-1.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-9102.sea19.amazon.com with ESMTP; 12 Feb 2020 22:34:13 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan2.iad.amazon.com [10.40.159.162]) by email-inbound-relay-1d-37fd6b3d.us-east-1.amazon.com (Postfix) with ESMTPS id 96E8728364D; Wed, 12 Feb 2020 22:34:04 +0000 (UTC) Received: from EX13D07UWB002.ant.amazon.com (10.43.161.131) by EX13MTAUWB001.ant.amazon.com (10.43.161.249) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:33:36 +0000 Received: from EX13MTAUWB001.ant.amazon.com (10.43.161.207) by EX13D07UWB002.ant.amazon.com (10.43.161.131) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:33:35 +0000 Received: from dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (172.22.96.68) by mail-relay.amazon.com (10.43.161.249) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Wed, 12 Feb 2020 22:33:35 +0000 Received: by dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (Postfix, from userid 4335130) id 01AA9400D1; Wed, 12 Feb 2020 22:33:35 +0000 (UTC) Date: Wed, 12 Feb 2020 22:33:35 +0000 From: Anchal Agarwal To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [RFC PATCH v3 08/12] xen/time: introduce xen_{save,restore}_steal_clock Message-ID: <20200212223335.GA4330@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Munehisa Kamata Currently, steal time accounting code in scheduler expects steal clock callback to provide monotonically increasing value. If the accounting code receives a smaller value than previous one, it uses a negative value to calculate steal time and results in incorrectly updated idle and steal time accounting. This breaks userspace tools which read /proc/stat. top - 08:05:35 up 2:12, 3 users, load average: 0.00, 0.07, 0.23 Tasks: 80 total, 1 running, 79 sleeping, 0 stopped, 0 zombie Cpu(s): 0.0%us, 0.0%sy, 0.0%ni,30100.0%id, 0.0%wa, 0.0%hi, 0.0%si,-1253874204672.0%st This can actually happen when a Xen PVHVM guest gets restored from hibernation, because such a restored guest is just a fresh domain from Xen perspective and the time information in runstate info starts over from scratch. This patch introduces xen_save_steal_clock() which saves current values in runstate info into per-cpu variables. Its couterpart, xen_restore_steal_clock(), sets offset if it found the current values in runstate info are smaller than previous ones. xen_steal_clock() is also modified to use the offset to ensure that scheduler only sees monotonically increasing number. Signed-off-by: Munehisa Kamata Signed-off-by: Anchal Agarwal --- Changes since V2: * separated the previously merged patches * In V2, introduction of save/restore steal clock and usage in hibernation code was merged in a single patch --- drivers/xen/time.c | 29 ++++++++++++++++++++++++++++- include/xen/xen-ops.h | 2 ++ 2 files changed, 30 insertions(+), 1 deletion(-) diff --git a/drivers/xen/time.c b/drivers/xen/time.c index 0968859c29d0..3560222cc0dd 100644 --- a/drivers/xen/time.c +++ b/drivers/xen/time.c @@ -23,6 +23,9 @@ static DEFINE_PER_CPU(struct vcpu_runstate_info, xen_runstate); static DEFINE_PER_CPU(u64[4], old_runstate_time); +static DEFINE_PER_CPU(u64, xen_prev_steal_clock); +static DEFINE_PER_CPU(u64, xen_steal_clock_offset); + /* return an consistent snapshot of 64-bit time/counter value */ static u64 get64(const u64 *p) { @@ -149,7 +152,7 @@ bool xen_vcpu_stolen(int vcpu) return per_cpu(xen_runstate, vcpu).state == RUNSTATE_runnable; } -u64 xen_steal_clock(int cpu) +static u64 __xen_steal_clock(int cpu) { struct vcpu_runstate_info state; @@ -157,6 +160,30 @@ u64 xen_steal_clock(int cpu) return state.time[RUNSTATE_runnable] + state.time[RUNSTATE_offline]; } +u64 xen_steal_clock(int cpu) +{ + return __xen_steal_clock(cpu) + per_cpu(xen_steal_clock_offset, cpu); +} + +void xen_save_steal_clock(int cpu) +{ + per_cpu(xen_prev_steal_clock, cpu) = xen_steal_clock(cpu); +} + +void xen_restore_steal_clock(int cpu) +{ + u64 steal_clock = __xen_steal_clock(cpu); + + if (per_cpu(xen_prev_steal_clock, cpu) > steal_clock) { + /* Need to update the offset */ + per_cpu(xen_steal_clock_offset, cpu) = + per_cpu(xen_prev_steal_clock, cpu) - steal_clock; + } else { + /* Avoid unnecessary steal clock warp */ + per_cpu(xen_steal_clock_offset, cpu) = 0; + } +} + void xen_setup_runstate_info(int cpu) { struct vcpu_register_runstate_memory_area area; diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h index 3b3992b5b0c2..12b3f4474a05 100644 --- a/include/xen/xen-ops.h +++ b/include/xen/xen-ops.h @@ -37,6 +37,8 @@ void xen_time_setup_guest(void); void xen_manage_runstate_time(int action); void xen_get_runstate_snapshot(struct vcpu_runstate_info *res); u64 xen_steal_clock(int cpu); +void xen_save_steal_clock(int cpu); +void xen_restore_steal_clock(int cpu); int xen_setup_shutdown_event(void); From patchwork Wed Feb 12 22:34:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anchal Agarwal X-Patchwork-Id: 11379295 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 88E71921 for ; Wed, 12 Feb 2020 22:34:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6894721734 for ; Wed, 12 Feb 2020 22:34:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="mY3E4OGE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729125AbgBLWeX (ORCPT ); Wed, 12 Feb 2020 17:34:23 -0500 Received: from smtp-fw-9101.amazon.com ([207.171.184.25]:61693 "EHLO smtp-fw-9101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727947AbgBLWeX (ORCPT ); Wed, 12 Feb 2020 17:34:23 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1581546863; x=1613082863; h=date:from:to:subject:message-id:mime-version; bh=Eo18FuPqTI4s9/8b+RyMmqnZX5xJ4fL1BD2xZjVWSBE=; b=mY3E4OGEZvstavDfNfa2/qa6u4Twa7Cm2DszTXho4H/Smv/MmIcvH71I YtV0ZXFPG8akppBAcxMti1No2Og4b3Ti/SIH5J5WA+V+RX6W0idp0cE7C +l4txKlcrV3B159hvg2TZgqbMIskdE4/f2XHNjtynCWVM2RJgblyiko2M Y=; IronPort-SDR: CAoTjaJQmXCSqypAs4vlySVkxQ/IlBFjWb07NalXRqztxgZBJy36fgeRw1UIfOlZSSKUHy7wPG GxFxRyu9NIIA== X-IronPort-AV: E=Sophos;i="5.70,434,1574121600"; d="scan'208";a="16327964" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-2a-6e2fc477.us-west-2.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-9101.sea19.amazon.com with ESMTP; 12 Feb 2020 22:34:21 +0000 Received: from EX13MTAUWC001.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan2.pdx.amazon.com [10.170.41.162]) by email-inbound-relay-2a-6e2fc477.us-west-2.amazon.com (Postfix) with ESMTPS id 7E329A24DF; Wed, 12 Feb 2020 22:34:19 +0000 (UTC) Received: from EX13D05UWC001.ant.amazon.com (10.43.162.82) by EX13MTAUWC001.ant.amazon.com (10.43.162.135) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:34:13 +0000 Received: from EX13MTAUWC001.ant.amazon.com (10.43.162.135) by EX13D05UWC001.ant.amazon.com (10.43.162.82) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:34:13 +0000 Received: from dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (172.22.96.68) by mail-relay.amazon.com (10.43.162.232) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Wed, 12 Feb 2020 22:34:13 +0000 Received: by dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (Postfix, from userid 4335130) id 58D23400D1; Wed, 12 Feb 2020 22:34:13 +0000 (UTC) Date: Wed, 12 Feb 2020 22:34:13 +0000 From: Anchal Agarwal To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [RFC PATCH v3 09/12] x86/xen: save and restore steal clock Message-ID: <20200212223413.GA4354@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Munehisa Kamata Save steal clock values of all present CPUs in the system core ops suspend callbacks. Also, restore a boot CPU's steal clock in the system core resume callback. For non-boot CPUs, restore after they're brought up, because runstate info for non-boot CPUs are not active until then. Signed-off-by: Munehisa Kamata Signed-off-by: Anchal Agarwal --- Changes since V2: * Separate patch to add save/restore call to suspend/resume code --- arch/x86/xen/suspend.c | 13 ++++++++++++- arch/x86/xen/time.c | 3 +++ 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c index 784c4484100b..dae0f74f5390 100644 --- a/arch/x86/xen/suspend.c +++ b/arch/x86/xen/suspend.c @@ -91,12 +91,20 @@ void xen_arch_suspend(void) static int xen_syscore_suspend(void) { struct xen_remove_from_physmap xrfp; - int ret; + int cpu, ret; /* Xen suspend does similar stuffs in its own logic */ if (xen_suspend_mode_is_xen_suspend()) return 0; + for_each_present_cpu(cpu) { + /* + * Nonboot CPUs are already offline, but the last copy of + * runstate info is still accessible. + */ + xen_save_steal_clock(cpu); + } + xrfp.domid = DOMID_SELF; xrfp.gpfn = __pa(HYPERVISOR_shared_info) >> PAGE_SHIFT; @@ -118,6 +126,9 @@ static void xen_syscore_resume(void) pvclock_resume(); + /* Nonboot CPUs will be resumed when they're brought up */ + xen_restore_steal_clock(smp_processor_id()); + gnttab_resume(); } diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index befbdd8b17f0..8cf632dda605 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -537,6 +537,9 @@ static void xen_hvm_setup_cpu_clockevents(void) { int cpu = smp_processor_id(); xen_setup_runstate_info(cpu); + if (cpu) + xen_restore_steal_clock(cpu); + /* * xen_setup_timer(cpu) - snprintf is bad in atomic context. Hence * doing it xen_hvm_cpu_notify (which gets called by smp_init during From patchwork Wed Feb 12 22:34:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anchal Agarwal X-Patchwork-Id: 11379303 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2E805921 for ; Wed, 12 Feb 2020 22:34:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0E6E4218AC for ; Wed, 12 Feb 2020 22:34:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="tD+1J8/G" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729199AbgBLWes (ORCPT ); Wed, 12 Feb 2020 17:34:48 -0500 Received: from smtp-fw-9101.amazon.com ([207.171.184.25]:61877 "EHLO smtp-fw-9101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727947AbgBLWes (ORCPT ); Wed, 12 Feb 2020 17:34:48 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1581546888; x=1613082888; h=date:from:to:subject:message-id:mime-version; bh=tYSU9iIsoDiHOrDtUYIpPVrJzHedrCrd1HEsqWaOGf0=; b=tD+1J8/GbJodCU7B5y1Kbz1Bu64/n3fcoZneWvH4rFY7ChaexmiKoAxJ rKdflZjgdYrtWXGR4A2BQH/vSMMEAXA2E26PnAKAbBp+1IakhRrcw5G0F 37FqG1v2wRGviETPJfk4R0MiKIj+dY6/75KopLV/AqoCjbkE98hCYl67X 8=; IronPort-SDR: bkSrtJsJHpidimijd2L1wIMETSIqwjC5vVxq1oCoMg6L/owqJK4HB0Xj7VHCDOcGTayR5JOFV8 X4CMSFr17QNw== X-IronPort-AV: E=Sophos;i="5.70,434,1574121600"; d="scan'208";a="16328108" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-2a-538b0bfb.us-west-2.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-9101.sea19.amazon.com with ESMTP; 12 Feb 2020 22:34:47 +0000 Received: from EX13MTAUWC001.ant.amazon.com (pdx4-ws-svc-p6-lb7-vlan3.pdx.amazon.com [10.170.41.166]) by email-inbound-relay-2a-538b0bfb.us-west-2.amazon.com (Postfix) with ESMTPS id E0121A28F3; Wed, 12 Feb 2020 22:34:45 +0000 (UTC) Received: from EX13D05UWC001.ant.amazon.com (10.43.162.82) by EX13MTAUWC001.ant.amazon.com (10.43.162.135) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:34:39 +0000 Received: from EX13MTAUWC001.ant.amazon.com (10.43.162.135) by EX13D05UWC001.ant.amazon.com (10.43.162.82) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:34:39 +0000 Received: from dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (172.22.96.68) by mail-relay.amazon.com (10.43.162.232) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Wed, 12 Feb 2020 22:34:39 +0000 Received: by dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (Postfix, from userid 4335130) id 83531400D1; Wed, 12 Feb 2020 22:34:39 +0000 (UTC) Date: Wed, 12 Feb 2020 22:34:39 +0000 From: Anchal Agarwal To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [RFC PATCH v3 10/12] xen: Introduce wrapper for save/restore sched clock offset Message-ID: <20200212223439.GA4444@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Introduce wrappers for save/restore xen_sched_clock_offset to be used by PM hibernation code to avoid system instability during resume. Signed-off-by: Anchal Agarwal --- Changes since V2: * Dropped marking tsc unstable during hibernation patch * Fixed issue with xen_sched_clock_offset during suspend/resume * On further interrogation and testing, the issue wasn't with tsc being stable/unstable --- arch/x86/xen/time.c | 15 +++++++++++++-- arch/x86/xen/xen-ops.h | 2 ++ 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index 8cf632dda605..eeb6d3d2eaab 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -379,12 +379,23 @@ static const struct pv_time_ops xen_time_ops __initconst = { static struct pvclock_vsyscall_time_info *xen_clock __read_mostly; static u64 xen_clock_value_saved; +/*This is needed to maintain a monotonic clock value during PM hibernation */ +void xen_save_sched_clock_offset(void) +{ + xen_clock_value_saved = xen_clocksource_read() - xen_sched_clock_offset; +} + +void xen_restore_sched_clock_offset(void) +{ + xen_sched_clock_offset = xen_clocksource_read() - xen_clock_value_saved; +} + void xen_save_time_memory_area(void) { struct vcpu_register_time_memory_area t; int ret; - xen_clock_value_saved = xen_clocksource_read() - xen_sched_clock_offset; + xen_save_sched_clock_offset(); if (!xen_clock) return; @@ -426,7 +437,7 @@ void xen_restore_time_memory_area(void) out: /* Need pvclock_resume() before using xen_clocksource_read(). */ pvclock_resume(); - xen_sched_clock_offset = xen_clocksource_read() - xen_clock_value_saved; + xen_restore_sched_clock_offset(); } static void xen_setup_vsyscall_time_info(void) diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index d84c357994bd..9f49124df033 100644 --- a/arch/x86/xen/xen-ops.h +++ b/arch/x86/xen/xen-ops.h @@ -72,6 +72,8 @@ void xen_save_time_memory_area(void); void xen_restore_time_memory_area(void); void xen_init_time_ops(void); void xen_hvm_init_time_ops(void); +void xen_save_sched_clock_offset(void); +void xen_restore_sched_clock_offset(void); irqreturn_t xen_debug_interrupt(int irq, void *dev_id); From patchwork Wed Feb 12 22:35:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anchal Agarwal X-Patchwork-Id: 11379313 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D6296921 for ; Wed, 12 Feb 2020 22:35:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B4FCB2173E for ; Wed, 12 Feb 2020 22:35:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="iatwNokw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728098AbgBLWfz (ORCPT ); Wed, 12 Feb 2020 17:35:55 -0500 Received: from smtp-fw-33001.amazon.com ([207.171.190.10]:20597 "EHLO smtp-fw-33001.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727947AbgBLWfz (ORCPT ); Wed, 12 Feb 2020 17:35:55 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1581546954; x=1613082954; h=date:from:to:subject:message-id:mime-version; bh=mAb4SIbaoDODH4/U698l6fYXrmrb6YPbZDM+uvQY0QE=; b=iatwNokwJfmqybGRbKGmmuyX4HVWBliDadeXDwfydFKfy7/e8scEqcBo EBgT6mSZGotmLe9gKupcL4xJLwiLGTFBTgTYq/W2dwGJQTBOiJZn/8+qG FonS8bsM0/5uAt9Te1wd1vJfkS5ZjDJUyw0LaUlZKtZEHvYvp46q2IE0j s=; IronPort-SDR: 1TWmY1HVjrLqoQ7uteZMkEOTJhXdjkOW3b8fpdoEoaiYwZhT6a8l//IPpK5Y8YqgCdgDuPuJ93 Y1bbRTNghAjA== X-IronPort-AV: E=Sophos;i="5.70,434,1574121600"; d="scan'208";a="26089661" Received: from sea32-co-svc-lb4-vlan3.sea.corp.amazon.com (HELO email-inbound-relay-1a-807d4a99.us-east-1.amazon.com) ([10.47.23.38]) by smtp-border-fw-out-33001.sea14.amazon.com with ESMTP; 12 Feb 2020 22:35:52 +0000 Received: from EX13MTAUEB002.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan2.iad.amazon.com [10.40.159.162]) by email-inbound-relay-1a-807d4a99.us-east-1.amazon.com (Postfix) with ESMTPS id 8A1EBA1D80; Wed, 12 Feb 2020 22:35:44 +0000 (UTC) Received: from EX13D08UEB001.ant.amazon.com (10.43.60.245) by EX13MTAUEB002.ant.amazon.com (10.43.60.12) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:35:19 +0000 Received: from EX13MTAUEA001.ant.amazon.com (10.43.61.82) by EX13D08UEB001.ant.amazon.com (10.43.60.245) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:35:19 +0000 Received: from dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (172.22.96.68) by mail-relay.amazon.com (10.43.61.243) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Wed, 12 Feb 2020 22:35:19 +0000 Received: by dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (Postfix, from userid 4335130) id 4B461400D1; Wed, 12 Feb 2020 22:35:19 +0000 (UTC) Date: Wed, 12 Feb 2020 22:35:19 +0000 From: Anchal Agarwal To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [RFC PATCH v3 11/12] xen: Update sched clock offset to avoid system instability in hibernation Message-ID: <20200212223519.GA4483@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Save/restore xen_sched_clock_offset in syscore suspend/resume during PM hibernation. Commit '867cefb4cb1012: ("xen: Fix x86 sched_clock() interface for xen")' fixes xen guest time handling during migration. A similar issue is seen during PM hibernation when system runs CPU intensive workload. Post resume pvclock resets the value to 0 however, xen sched_clock_offset is never updated. System instability is seen during resume from hibernation when system is under heavy CPU load. Since xen_sched_clock_offset is not updated, system does not see the monotonic clock value and the scheduler would then think that heavy CPU hog tasks need more time in CPU, causing the system to freeze Signed-off-by: Anchal Agarwal --- Changes Since V2: * New patch to update sched clock offset during hibernation to avoid hungups during resume when running a CPU intensive workload --- arch/x86/xen/suspend.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c index dae0f74f5390..7e5275944810 100644 --- a/arch/x86/xen/suspend.c +++ b/arch/x86/xen/suspend.c @@ -105,6 +105,8 @@ static int xen_syscore_suspend(void) xen_save_steal_clock(cpu); } + xen_save_sched_clock_offset(); + xrfp.domid = DOMID_SELF; xrfp.gpfn = __pa(HYPERVISOR_shared_info) >> PAGE_SHIFT; @@ -126,6 +128,12 @@ static void xen_syscore_resume(void) pvclock_resume(); + /* + * Restore xen_sched_clock_offset during resume to maintain + * monotonic clock value + */ + xen_restore_sched_clock_offset(); + /* Nonboot CPUs will be resumed when they're brought up */ xen_restore_steal_clock(smp_processor_id()); From patchwork Wed Feb 12 22:35:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anchal Agarwal X-Patchwork-Id: 11379325 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 02A201805 for ; Wed, 12 Feb 2020 22:36:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D705A2082F for ; Wed, 12 Feb 2020 22:36:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="OBTbLSy3" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729195AbgBLWgX (ORCPT ); Wed, 12 Feb 2020 17:36:23 -0500 Received: from smtp-fw-4101.amazon.com ([72.21.198.25]:14698 "EHLO smtp-fw-4101.amazon.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727947AbgBLWgX (ORCPT ); Wed, 12 Feb 2020 17:36:23 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1581546982; x=1613082982; h=date:from:to:subject:message-id:mime-version; bh=ZcT5NL3HFOPFbym2IiAARR+k8Y7xo5J+zpygwD2ALWc=; b=OBTbLSy3uAILFo/AKR2w77FqbxDrXMS0XsBY6hCNboXUgPEOEGQNiojN SCwczM2RxJ+CFTGBy0emzyV8tgXCjP1eSguAFPoShKCMJfUGE4RQM2WHq VAWYow1x5lP0lQ1mJ5nFZM2r1AscK5HPOUGEbwBI/HnVOi6pEYW1RWLZv M=; IronPort-SDR: RuG58dnJ7bK0jmVNwi+pnsRoVw06xDHGaPsu5B6jHAddTjNNYzGJxuu6rUzhRt+WNLOPfopBFM 6yF3lWoXEQ8Q== X-IronPort-AV: E=Sophos;i="5.70,434,1574121600"; d="scan'208";a="16854725" Received: from iad12-co-svc-p1-lb1-vlan3.amazon.com (HELO email-inbound-relay-1e-c7c08562.us-east-1.amazon.com) ([10.43.8.6]) by smtp-border-fw-out-4101.iad4.amazon.com with ESMTP; 12 Feb 2020 22:36:22 +0000 Received: from EX13MTAUWB001.ant.amazon.com (iad55-ws-svc-p15-lb9-vlan2.iad.amazon.com [10.40.159.162]) by email-inbound-relay-1e-c7c08562.us-east-1.amazon.com (Postfix) with ESMTPS id 910E62427DA; Wed, 12 Feb 2020 22:36:14 +0000 (UTC) Received: from EX13D01UWB002.ant.amazon.com (10.43.161.136) by EX13MTAUWB001.ant.amazon.com (10.43.161.207) with Microsoft SMTP Server (TLS) id 15.0.1367.3; Wed, 12 Feb 2020 22:35:52 +0000 Received: from EX13MTAUWB001.ant.amazon.com (10.43.161.207) by EX13d01UWB002.ant.amazon.com (10.43.161.136) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 12 Feb 2020 22:35:52 +0000 Received: from dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (172.22.96.68) by mail-relay.amazon.com (10.43.161.249) with Microsoft SMTP Server id 15.0.1367.3 via Frontend Transport; Wed, 12 Feb 2020 22:35:52 +0000 Received: by dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com (Postfix, from userid 4335130) id 28812400D1; Wed, 12 Feb 2020 22:35:52 +0000 (UTC) Date: Wed, 12 Feb 2020 22:35:52 +0000 From: Anchal Agarwal To: , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [RFC PATCH v3 12/12] PM / hibernate: update the resume offset on SNAPSHOT_SET_SWAP_AREA Message-ID: <20200212223552.GA4609@dev-dsk-anchalag-2a-9c2d1d96.us-west-2.amazon.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Aleksei Besogonov The SNAPSHOT_SET_SWAP_AREA is supposed to be used to set the hibernation offset on a running kernel to enable hibernating to a swap file. However, it doesn't actually update the swsusp_resume_block variable. As a result, the hibernation fails at the last step (after all the data is written out) in the validation of the swap signature in mark_swapfiles(). Before this patch, the command line processing was the only place where swsusp_resume_block was set. Signed-off-by: Aleksei Besogonov Signed-off-by: Munehisa Kamata Signed-off-by: Anchal Agarwal --- Changes since V2: None --- kernel/power/user.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/kernel/power/user.c b/kernel/power/user.c index 77438954cc2b..d396e313cb7b 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -374,8 +374,12 @@ static long snapshot_ioctl(struct file *filp, unsigned int cmd, if (swdev) { offset = swap_area.offset; data->swap = swap_type_of(swdev, offset, NULL); - if (data->swap < 0) + if (data->swap < 0) { error = -ENODEV; + } else { + swsusp_resume_device = swdev; + swsusp_resume_block = offset; + } } else { data->swap = -1; error = -EINVAL;